This invention relates to an image reader apparatus for optically reading an image of an object and, more particularly to an image reader apparatus for reading an object image line by line by means of a line sensor in accordance with a command from an external apparatus such as a computer and successively transferring read line data of the image to the external apparatus.
A known image reader apparatus of this type reads an image on a sheet-like medium such as a film image by means of a CCD line sensor. This apparatus operates as follows. The object such as a film is moved by a specified distance corresponding to the width of one line readable by the CCD line sensor. The CCD line sensor reads the image line by line in accordance with an amount of light transmitted through the medium and incident thereupon. A specified processing is applied to image signals each representing one line of image read by the CCD line sensor, and the thus obtained image data are successively transferred to a computer.
In the above prior art apparatus, such image is read by repeatedly moving the medium, after one line of image is read and transferred, to read and transfer a next line of image. Accordingly, it disadvantageously takes a long time to complete the entire reading of an image on a sheet-like medium.